弗吉尼亚栎种子育苗和无性繁育技术

随着杭州湾跨海大桥和杭州湾新区的建设,在沿海防护林和新区绿化过程中极缺优良常绿耐盐碱树种.为此,2003年从美国引进弗吉尼亚栎(简称弗栎)种子播种育苗,2006年进行扦插繁苗试验,并通过一系列的试验以求形成苗木规模化生产技术体系.结果发现,弗栎种子易受象鼻虫危害,新引进种子必须进行杀虫处理;由于弗栎种子发芽和出苗不整齐,最好采取催芽播种和加温育苗,以提高出苗率,防止烂种;弗栎实生幼苗生长具有明显的抽梢-停梢生长阶段,春季有3次抽梢,秋季有1次明显抽梢期;在整个生长过程中,温度在30℃以下,生长速度随温度的升高而加快,大于32℃后,生长速度下降,在夏季高温会出现长时间的停梢现象.弗栎可采用扦插繁苗,扦插时间以秋季9月上、中旬为宜,插穗应选择当年生粗度3 mm以上、节间紧的枝条下部为宜,插穗以留3叶为好,插穗处理以15 000～20 000 mg/kg萘乙酸沾根处理为宜.     

美国栎属种源引种、变异研究:种子及苗期生长变异

对从美国３个州（宾夕法尼亚、纽约和田纳西州）引进的栎属３个树种北方红栎、柳叶栎和红栎的２１个种源进行了两次播种和容器育苗试验。初步掌握了栎属种子砂床播种、芽苗移栽、容器育苗的关键技术。对栎属种子的发芽、芽苗和苗木的生长过程等有了一定的了解。发现栎属不同树种间和种内种源、家系间在种子体积、千粒重、发芽率、３０ｄ萌叶率和苗高生长等性状均存在极显著变异,试验数据表明种子体积北方红栎为大（其中宾夕法尼亚州家系１７２最大）,其次是红栎和柳叶栎。千粒重以北方红栎为重（其中宾夕法尼亚州家系１７２最重）,其次是红栎和柳叶栎。发芽率为北方红栎最高（其中宾夕法尼亚州家系１９１为１００％）,其次是红栎和柳叶栎。３０ｄ萌叶率和苗高生长以柳叶栎为高（田纳西州种源９７０１ＴＮ最高）,其次是红栎和北方红栎。在种间和种内不同种源、家系间种子千粒重与年终苗高生长相关不显著。     

北方地区皂荚种子及荚果形态特征的地理变异

对我国皂荚北方自然分布区7个产地采集的皂荚种子及部分荚果进行取样测定,分别测定荚果及种子10项形态指标,结果发现:各指标在同一群体不同家系间差异显著;不同群体间,除荚果宽、种子长、荚果长宽比外,其余指标差异均达显著或极显著水平;单荚果质量、荚果长度、荚果宽度及荚果长宽比表现为同地理经度上的南北变异;荚果宽厚比及种子长宽比,表现为同地理纬度的东西变异;荚果厚度、种子长度与种子长宽比表现为西南-东北向变异;种子千粒质量无明显的地理变异规律,主要与分布地点的海拔高度、水分、太阳辐射及炎热状况的综合作用有关.     

大叶栎优树种子性状变异研究

对87株大叶栎(Castanopsis fissa)初选优树种子性状变异及对苗期生长的影响进行研究,结果表明:种子性状在家系间存在极显著差异。相关分析,种子长、宽与子代苗高、地径呈极显著正相关;种子长宽比与子代苗高、地径呈极微弱的负相关;种子千粒重与子代苗高、地径表现极显著的正相关;发芽率与其它性状的相关均未达到显著水平。说明种子长、种子宽、千粒重对子代的苗高、地径生长有明显的影响。     

红榉不同种源种子形态性状变异

研究了红榉自然分布区4个省份15个种源的种子长、宽、长宽比及千粒重等性状的变异。结果表明:(1)红榉种源间种子长、宽、长宽比和千粒重等性状的差异均达极显著水平,且种源水平上各性状的遗传力分别为0.901 8、0.921 0、0.922 1和0.900 8,单株水平上的遗传力分别为0.926 0、0.979 2、0.932 6和0.992 5,表明红榉种子形态性状存在着丰富的遗传变异,且受到中等程度以上的遗传控制;(2)相关分析表明,红榉种子长、宽及千粒重之间存在着极显著相关关系,且红榉种子性状无明显的经向和纬向变异,种子长主要受年均温和无霜期影响,种子宽主要受1月均温影响,而千粒重主要受年均温的影响;(3)聚类分析表明,红榉种子形态特征地理变异呈现区域板块变异模式和随机变异模式等。     

遮荫对弗吉尼亚栎苗木生长及光合-荧光参数的影响

[目的]揭示美国引进树种弗吉尼亚栎幼苗对光照强度的响应特征,为弗吉尼亚栎的引种驯化和高效栽培提供科学依据。[方法]采用人工遮荫法,研究3种光环境下(全光——100%自然光、中度遮荫——50%自然光和强度遮荫——25%自然光)弗吉尼亚栎苗木生长、光合作用以及叶绿素荧光参数的变化。[结果]表明:中度遮荫明显促进弗吉尼亚栎苗高生长(P0.05),但对地径生长影响不明显;而强度遮荫条件下,地径生长受到明显抑制(P0.05),苗高虽有所下降,但与对照相比差异不明显。对弗吉尼亚栎光响应曲线的观测表明:与全光条件相比,中度遮荫条件下,弗吉尼亚栎叶片暗呼吸速率(Rd)、光饱和点(LSP)以及光补偿点(LCP)均明显下降(P0.05),说明适度的遮荫有助于提高弗吉尼亚栎对光的利用效率,促进干物质的积累;而强度遮荫条件下,光补偿点和光饱和点明显上升,暗呼吸速率明显增加(P0.05)。遮荫并未对表观量子效率(α)和最大净光合速率(P_(max))产生明显的影响。进一步对叶绿素荧光参数分析发现,遮荫条件下,PSⅡ最大光化学量子产量(F_v/F_m)和实际光量子产量(Yield)有所增加,但均在正常范围,说明遮荫对PSⅡ活性并未产生胁迫。[结论]弗吉尼亚栎幼苗对遮荫均具有一定的耐受性,中度遮荫有利于苗高生长;而强度遮荫不利于干物质的积累。因此,建议在营林以及人工栽培过程中维持50%以上的自然光照。     

不同居群连香树种子形态变异及其与环境因子相关性分析

分析不同居群连香树种子形态变异及其与环境因子相关性,结果表明:不同居群间种子长宽、种翅长宽和千粒重均存在显著差异,按大小排序均为白龙江种>药山种>美姑种,种子形态与纬度、气温、海拔、降水等环境因子之间有显著关系,且呈现较好的稳定性。     

太白山油松球果和种子形态变异分析

文章通过对陕西省太白山油松天然群体中的30个家系（单株）的球果和种子表型性状进行统计分析，讨论了油松种源间和种源内家系间的遗传变异与相关性。结果表明，油松种实性状在家系间存在着极其丰富的遗传变异。油松果重、果高、果宽和种长的家系遗传力都处于较高的水平（0．5696～0．7103），呈现出中强度遗传，而种子高度和种子宽度的家系遗传力较低。油松球果性状之间的相关关系均达极显著水平；而种子性状彼此间相关关系也比较密切。球果性状中果宽与种子各性状间均存在显著或极显著正向相关，而球果高度与种子性状间相关不显著，果重除与种子宽度间相关不显著外，与种长和种高间相关均达到显著或极显著水平。种实性状对千粒重的回归分析表明，种长、种宽和种高对千粒重的贡献显著，而果宽对千粒重的影响较小。     

班克木种子形态及发芽特征在种内与种间的变异

对引自澳大利亚的班克木属5个种18个种源进行种子形态、质量以及发芽特征测定,结果表明:班克木属种子形态、质量和发芽特征在种间和种内均有不同的差异表现;香花班克木种子千粒质量最大,约106.5 g,为其他种的4～9倍;种子千粒质量与发芽率无显著相关;除红花班克木在试验期间未发芽外,其余4个种的发芽率皆高于60％,强力班克木发芽率最高,约80％;长圆叶班克木和强力班克木种子发芽速度最快,而香花班克木发芽速度最慢;发芽始期、发芽速度、发芽率、胚轴长、胚根长都和经度呈极显著正相关(P＜0.01),即自西澳的珀斯至东澳的塔斯马尼亚地区,种子的发芽始期越晚,发芽速度慢,发芽率越高,胚轴和胚根的生长量越大.对于5种班克木的发芽特征的研究表明:强力班克木在广州的适应性最强,其发芽率最高,发芽速度最快,发芽最早且胚根长度最大.     

石栎属和栎属5个树种的幼苗形态特征

就壳斗科中的石栎属和栎属5个树种的种子(果实)及幼苗的整个发展过程和种子、苗木的生产技术做了细致的研究,并对各树种的种子及幼苗进行观察、记载和绘制成图。     

苦槠种子形态性状的地理变异分析

苦槠(Castanopsis sclerophylla (Lindl.) Schott.)为壳斗科(Fagaceae)栲属(Castanopsis (D. Don.) Spach.)植物[1],是亚热带地区常绿阔叶林的重要建群树种,也是亚热带常绿阔叶林次生演替阶段重要的先锋树种,对群落的组成、外貌、功能等都有一定控制作用[2].苦槠作为优良多用途树种,其生态效益、经济价值、食品保健功用及其在园林绿化中的地位已逐渐得到认可[3-4].目前,国内对苦槠的研究已有了一定基础,但对苦槠种群遗传学研究较少.种子是物种遗传变异的重要特征之一,在分类和遗传上具有重要的价值[5],种子形态不仅决定其扩散能力,也影响到种子的萌发和幼苗定植,进而影响到种群的分布格局[6].研究苦槠种子性状变异及其地理分化,对了解苦槠种群遗传分布格局具有重要意义,进而也可为苦槠天然林的保护和人工林的营建提供理论参考.     

不同种源蒙古栎种子表型性状与淀粉含量的变异分析

The study aims at compare and analyze the variation pattern of the phenotype characters and starch content of Quercus mongolica seed of different provenances. The length, width, length/width ratio, single kernel weight of Q. mongolica seeds from 16 natural distribution regions in China were measured and analyzed. The results showed that there were extremely significant differences among seeds from different region in seed characters. The length and width of seeds ranged from 14.76 mm to 21.08 mm and from 11.87 mm to 15.31 mm, respectively. The length/width ratio of seeds ranged from 1.21 to 1.49. The single kernel weight ranged from 0.60 g to 1.78 g and the contents of starch ranged from 4.42 g·kg^-1 to 5.48 g·kg^-1. The length of seeds has a extremely significant positive correlation with the width and weight of seed, and the width of seed had a significant positive correlation with the weight of seed. The seed width has a significant positive correlation with contents of starch. The width of seeds had a significant negative correlation with altitude, and had a positive correlation with July’s mean temperature. The weight of seed had a significant positive correlation with July's mean temperature too. The correlation of the other phenotypic character and starch content of Q. mongolica seed to geographical climate factors was not significant. According to the results of cluster analysis, sixteen Q. mongolica provenances could be divided into three groups with big fruit and high starch content, middle fruit and starch content, small fruit and low starch content, in which the provenances from Dailing of Heilongjiang Province, Benxi of Liaoning Province and Dayangshu of Inner Mongolia were the superior provenances.     

无患子种实形态及经济性状的地理变异

对我国无患子分布区7个产地的种实形态性状及种仁含油率进行取样测定.方差分析结果表明,种实各性状在产地内单株间的变异程度不同,但多数性状在多数产地内均存在丰富的变异,在产地内进行单株选择是可行的.在不同产地间,无患子种实各性状均存在显著差异,河南西峡产地果实和种子较大,与其它产地间差异显著.无患子种仁含油率产地间变异系数最小,与地理气候因子间不存在明显的相关性,而种子质量、种子出仁率在不同产地间变异系数相对较大,且与种实大小显著正相关,可以通过选择较大的果实、种子来提高产油量.聚类及相关性分析表明,在一定程度上,无患子种实大小和种子出仁率有从低纬度产地向高纬度产地变大的变异趋势,因此无患子高产油单株的选择应重点在较高纬度产地果实、种子较大的个体中进行.     

Drought and fire suppression lead to rapid forest composition change in a forest-prairie ecotone

Altered fire regimes and increased drought can lead to major vegetation changes, especially in ecotones. A decrease in fire can lead to woody species encroachment in prairies and increasing forest stand density. The threat of global climate change raises questions about potential increases in the length, severity, and incidence of droughts substantially altering species composition. Re-measured upland forests in south-central North America's midcontinent forest-prairie ecotone exhibited major changes in woody species composition and structure over fifty years and successional trajectories appeared to favor invasive Juniperus virginiana L. over the previous dominant Quercus species. The objective of this study was to determine whether climate and fire exclusion affected the recruitment history of dominant woody species in these upland forests located near the xeric western edge of the eastern deciduous forest biome of North America. We removed cores and cross-sections from 992 J. virginiana, Quercus marilandica Münchh. and Q. stellata Wangenh. trees from eleven forest stands located across central and northwest Oklahoma, and determined their ages using standard dendrochronological methods. Recruitment of all species increased following a severe mid-20th century drought, but a rapid increase in J. virginiana recruitment and decrease in Quercus recruitment appeared to be linked to a decrease in fire. Future fire regime changes and increased drought due to global climate change could lead to widespread shifts from Quercus- to Juniperus- dominated forests and cause substantial changes to ecosystem services.     

珍贵药用植物三尖杉种子大小的变异

对云南省宁蒗县珍贵药用植物三尖杉种子大小性状变异的研究表明 :种子的长度、宽度、厚度、长度与宽度比、长度与厚度比、宽度与厚度比和重量等性状变异均为连续分布的数量性状 ,它们的平均值分别为 18 2 9± 2 4 5mm、 9 4 2± 0 6 5mm、 7 71± 0 5 6mm、 1 94± 0 2 4、 2 38± 0 34、 1 2 2± 0 0 6和 0 4 6 3± 0 10 6g ;变异系数分别为 13 37%、 6 88%、 7 2 2 %、 12 2 2 %、 14 16 %、 4 84 %和 2 3 0 2 %。     

6个栓皮栎种源种子形态及其幼苗生长的比较

[Objective]To compare the differences of seed morphological characters among provinces of Quercus variabilis Bl.,and explore the adaptive growth status of seedlings growing in the central distribution area. [Method]The seeds of 6 Q. variabilis provenances from six provinceswerecollected, and the seedlings were cultivated and transplanted to experimental field in the centre of natural distribution range (Wuhan Jiufeng National Forest Park), then the seed morphology and one-year seedling growth traitswere surveyed. [Result](1)There were significantor extremely significantdifferences among provenances in seed length, seed width, seed length/width ratio and 100-seed mass, the order of seed length among provenances was Beijing Provenance (22.28 mm),Hubei Provenance (22.10 mm), He'nan Provenance (20.80 mm), Shaanxi Provenance (19.57 mm), Yunnan Provenance (18.93 mm)and Liaoning Provenance (18.81 mm), the seed width of Beijing Provenance (19.71 mm) and Hubei Provenance (19.16 mm) was higher than that of the others, the seed length/width ratio of He'nan Provenance (1.38) was extremely significantly higher than that of the others; (2)There were significant or extremely significant differences among provenances in seedling height, ground diameter, leaf number, branching number and seedling height/ground diameter, the Beijing Provenance and Hubei Provenance were better in seedling height and leaf number, which were respectively 19.54 cm and 20.26 cm, 8.32 leaves and 9.50 leaves; (3)A decreasing trend with time for seedling growth traits among provenances was found; (4)There was a positive relationship between seed morphological characters and seedling growth traits except seed length/width ratio; the leaf number was significantly related to ground diameter and branching number and the seedling height and leaf number were closely related to the seed morphological characters; (5)It showed a decreasing trend with the growth time in the relationship between seedling growth traits and 100-seed mass. [Conclusion]The seedlings of Beijing Provenance and Hubei Provenance grew better in the experimental field which might be related to their larger seed mass, and the Yunnan Provenance in the south margin and the Liaoning Provenance in the north margin of distribution area of Q. variabilis grew weaker than the provenances in the centre of distribution area.With the effect of climate change, provenances in the margin of distribution area may lose in the community competition in the seedling stage if it cannot take advantage of its dispersal and settlement and affected by the disadvantage of growth and competition, so that the distribution and population renewal would surely be affected.     

不同栽培树形对油橄榄品种果实产量的效应

Longnan City in Gansu Province is the largest base of olive production in China. In the olive orchard locating in Wudu District of Longnan City, thirty trees were sampled each of three cultivars, ‘Leccino’, ‘Chenggu32’, ‘Ezhi8’, with monoconical and vase training system. After planted with density of 5×6 m in 1992, each sample tree was investigated to determine the yield fresh fruit in five different years. The results of survey and analysis showed that there were significant differences of fruit yield among 5 years and 3 cultivars. Different canopy shapes yielded some effect on fruit setting rate and yield of different cultivars in different years. During first fruiting period in the fourth/sixth year after planting, fruit setting rate and yield of ‘Leccino’ with monocone were more 6.7% and 0.15 kg than those with vase and those of ‘Ezhi8’ and ‘Chenggu32’ with vase were more 20%, 10% and 0.18 kg, 0.09 kg than those with monocone. With the increase of tree age, fruit set and yield of ‘Leccino’ and ‘Ezhi8’ with vase was more than those of monocone. In 2011, average yields per tree of ‘Leccino’ and ‘Ezhi8’ with vase were more 13.35 kg and 6.85 kg than those with monocone. And the highest yield per tree of ‘Leccino’ with vase was 75 kg, more 16 kg than that of monocone. Fruit trees with yield over 35 kg of ‘Leccino’ and 25 kg of ‘Ezhi8’ with vase accounted for 80% and 46.7%, more 40% and 30.01% than those of monocone. It was concluded that vase training system would produce higher yield of ‘Leccino’ and ‘Ezhi8’ and its effect and advantages were gradually prominent with increase age. As for ‘Chenggu32’, monocone got a slightly higher yield than that of vase and in 2011 fruit trees with yield over 15 kg accounted for 25%, more 8.34% than vase. The difference between two training system of this cultivar was not obvious.     

温度对越南黄花梨种子萌发的影响

正温度是影响种子萌发的主要因素,也是决定种子萌发速度的首要条件,适宜的发芽温度是种子萌发所必需的环境条件之一,摸清种子萌发的适宜温度对指导农林业苗木生产实践具有重要意义[1-2]。不同植物的种子由于习性、生境和生理生态学等方面的差异,其最适的发芽温度差异较大[3-5]。越南黄花梨(Dalbergia tonkinensis Prain),越南名"su'a",又名越南黄檀、通京黄檀、越南香枝木等[6-7],是蝶形花科黄檀属的一种速生落叶乔